Holmes etal
bumpers



Dec. 6, 1966 G. D. HOLMES ETAL 3,289,813

BUMPERS 5 Sheets-Sheet 1 Filed March 1.2, 1965 FIG].

Iruvznrroes GORDON D4 HOLMES & BY WILLIAM J. RICHMOND j 2 VA on Dec. 6,1966 G. D. HOLMES ETAL 3,289,813

BUMPERS Filed March 12. 1965 5 Sheets-Sheet 2 INVENTOES GORDON D. HOLMES8- By WILLIAM J. RICHMOND T BR ATToeuEv 1966 G. D. HOLMES ETAL 3,

BUMPERS Filed March 12. 1965 5 Sheets-Sheet 4 INVENTOES GORDON D HOLMES& By WILLIAM JRICHMOND THEIR A'Y-rocausv Dec. 6, 1966 Filed March 12,1965 G. D. HOLMES ETAL.

BUMPERS 5 Sheets-Sheet 5 Imvam'osas GORDON D HOLMES & WILLIAM J RICHMONDTHEjR ATTQRNEN United States Patent 3,289,813 BUMPERS Gordon DavidHolmes, Worksop, and WIIham James Richmond, Shetfield, England,assignors to Davy and United Engineering Company Limited, Sheffield,England Filed Mar. 12, 1965, Ser. No. 439,321 Claims priority,application Great Britain, Mar. 16, 1964, 11,078/64 7 Claims. (Cl.198-427) This invention relates to bumpers; for example, when a steelslab is discharged from a re-heating furnace it slides down a ramp ontoa roller table and its travel across the table is arrested by a bumper.

The conventional furnace bumper is usually an expensive mechanism,combining castings and fabrications, and incorporating spring orhydraulic shock absorbers. Such a structure is unable to withstandrepeated impact and associated shock waves and as a result it invariablybreaks down after limited service, involving lengthy and expensiverenovations.

According to the present invention a bumper comprises an impactreceiving member suspended from a suspension member and having a massconnected thereto by connecting means such that movement of the impactmember from its rest position moves the mass upwards.

In a preferred form the mass is arranged to move up and down andinclined plane, so that friction between the mass and the inclinedsurface produces a damping effect. The connecting means preferablyprovide a mechanical advantage.

In one form the impact member is secured to intermediate points of aplurality of suspension members, in the form of ropes, chains or wires,one end of each suspension member being fixed and the other end beingconnected to the mass through a pulley system. In another form theconnecting means comprise a bell crank system.

The impact member is preferably a horizontal elongate plate with itslength normal to the axes of the rolls of a roller table and its loweredge scalloped to suit the table rollers and allow a part of the impactmember to be below the top of the rollers. This obviates any possibilityof an impacting slab getting underneath the impact member. Preferablythe masses are located behind the table drive box to give freedom fromscale and easy access.

Two embodiments of furnace bumper in accordance with the invention willnow be described by way of example only, with reference to theaccompanying drawings of which:

FIGURE 1 is a front elevation of a first furnace bumper,

FIGURE 2 is a section on the line II-II of FIGURE 1,

FIGURE 3 is a plan view of an alternative embodiment of a furnacebumper,

FIGURE 4 is a section on the line IVIV of FIG URE 3, and

FIGURE 5 is a section on the line V-V of FIG- URE 4.

Referring to FIGURES 1 and 2, a roller table 12 having rollers 13, isarranged to receive from a furnace (not shown) slabs 14 travelling inthe direction of arrow V. A bumper 15 is arranged to arrest the slabs onthe roller table.

The bumper 15 comprises an elongate rigid impact receiving member in theform of a plate 16, adjacent to the edge of the roller table, and havingits length normal to the axes 17 of the rolls 13. The lower edge 18 ofthe impact plate 16 is scalloped to suit the table rollers and allow apart of the plate to be below the top of the rollers.

Patented Dec. 6, 1966 The impact plate 16 is suspended from fourflexible suspension members 20, 21, 22 and 23, in the form of wireropes. These may alternatively be chains or the like. The upper end ofeach rope is pivotally attached at 24 to a support structure, anintermediate point 25 of each rope is secured to the back of the impactplate, that is the side remote from the impacting face 26, and the lowerend 27 of each rope is pivotally secured at 28 to a pulley block 30.

Between the impact plate and its pulley block, each rope passes betwenthe table rollers and through a pair of guide pulleys 31, 32, pulley 31being ambushed between fianges 33 of pulley 32.

Other ropes 34 pass over pulley wheels 35 of each of the pulley blocks30, one end of each rope 34 being pivotally secured to the foundations36, and the other end being attached to a mass 37. In the system shownthere are two masses 37a, 3712, the weight of mass 370 being carried byropes 20 and 21, and the weight of mass 37b being carried by ropes 22and 23.

Air cylinders (not shown) may be mounted on the supporting framework oron the table drive box behind the impact plate to restore the plate toits neutral position in the event of a slab sticking on the roller tableafter striking the plate.

In operation a hot slab is ejected from a furnace, slides across theroller table in the direction of arrow V, and strikes the plate 16. Theplate is displaced horizontally, thus inclining the suspension ropes andlifting the pulley block 30 through a distance proportional to thathorizontal displacement. Because of the pulleys 30 the masses are liftedtwice as far as the pulley blocks to obtain a mechanical advantage. Theeffect of this is to transform the kinetic energy of the slab (minus anyimpact slab deformation or friction losses) into potential energy in themasses 37. The masses then fall again returning the plate to its neutralposition and pushing the slab back to the central position on the table.This last phase is assisted, if necessary, by air cylinders which(though not connected to the plate), can push on the back of the plate.The pulleys 31, 32 guide the ropes and serve to control the masses.

The bumper shown in FIGURES 3, 4 and 5 has a similar impact plate 16arranged at one side of a furnace delivery roller table 12 havingrollers 13. The back of the impact bar is secured as in the embodimentof FIG- URES 1 and 2 to intermediate points of six wire ropes 38 theupper ends of which are pivotally secured at 39 to an overhead support40 and the lower ends of which are pivotally secured at 41 to one arm 42of a bell crank mechanism 43. An intermediate part 44 of the bell crankmechanism is pivotally mounted on the support 45 and the other arm 46 ofthe bell crank mechanism is pivotally secured to a horizontal connectinglink 47. The other end of the connecting link is pivotally secured at 48to one arm 50 of a second bell crank mechanism 51. An intermediate part52 of the bell crank mechanism 51 is pivotally mounted on the support 45and the other arm 53 of the mechanism 51 extends into a pocket 56 in amass 57, and has two arcuate bearing surfaces 58, 59 bearing against theupper and lower sides of the pocket respectively. As best seen in FIGURE3 there are three: large masses 57a, 57b and 570 each of which has twopockets 56 into which an arm 53 of a bell crank lever associated with adifferent rope 38 extends. Each mass 57 is arranged to slide up and downinclined plane surfaces 60 of a pair of supports 61, mounted on afoundation 62. The friction between the mass and surfaces 60 increasesthe effectiveness of the bumper both by reducing the stroke of theimpact plate, and introducing a damping effect which reduces the amountby which the slab is thrown back.

The roller table drive box is shown at 63 and it will be seen that thehorizontal link 47 passes under this drive box so that the masses 57 andslides 61 are behind the table drive box giving freedom from scale andeasy access.

In operation when a slab hits the impact plate 16 driving it from itsrest position shown, with the ropes 38 vertical, the movement of theplate 16 acts through the bell crank mechanism and link to drive themasses 57 up the surfaces 60, thus converting the kinetic energy of theslab to potential energy of the masses and frictional losses at theslides. The relative lengths of the arms of the bell cranks are designedto give a mechanical advantage as in the pulley block arrangement. Themasses then fall gradually to their original position pulling the slabback to the centre of the table.

The advantages of these designs are that there are no welds directlysubjected to impact; the bumper is cheaper to manufacture and maintainthan conventional bumpers; spare suspension ropes cost little and arequickly changed; little expensive machining is required, and shock loadsare confined to a robust impact member. The loads in the other parts ofthe device are gradually applied.

In accordance with the provisions of the patent statutes, we haveexplained the principle and operation of our invention and haveillustrated and described what we consider to represent the bestembodiment thereof. However, we desire to have it understood that withinthe scope of the appended claims, the invention may be prac ticedotherwise than as specifically illustrated and described.

We claim:

1. A bumper comprising a support, a plurality of flexible suspensionmembers, an impact receiving plate secured to said flexible suspensionmembers intermediate their ends, the upper ends of said flexiblesuspension members being secured to said support, a mass, connectingmeans for connecting the mass to the lower ends of said flexiblesuspension members such that movement of the impact receiving plate froma rest position moves the mass upward.

2. A bumper according to claim 1 in which the connecting means includesa device having a mechanical advantage to increase the effective weightof the mass.

3. A bumper according to claim 1 in which the lower ends of thesuspension members carry pulleys and the mass is connected to ropes orthe like passing over the pulleys.

4. A bumper according to claim 3 including guide means associated witheach suspension member located below the impact plate for guiding it inits movement.

5. A bumper according to claim 1 in which the connecting means betweeneach suspension member and the mass comprises a first pivotally mountedbell crank mechanism having one arm pivotally connected to thesuspension member and the other arm pivotally connected to one end of alink, a second pivotally mounted bell crank mechanism having one armpivotally connected to the other end of the link and a second arm incontact with the mass.

6. A bumper according to claim 5 in which the second arm of each secondbell crank mechanism extends into a pocket in the mass and has bearingsurfaces pivotally contacting the upper and lower walls of the bore.

7. In combination with a slab furnace delivery table having rollsadapted to support workpieces and drive means for at least some of therolls arranged on one side of said table, a bumper comprising a support,a plurality of flexible suspension members having one end connected tosaid support, an impact receiving plate extending normal to the axes ofthe rolls and above the level of the rolls arranged to be engaged byworkpieces supported by said rolls and being connected to said flexiblesuspension members intermediate their ends, a weighted member connectedto said flexible suspension members and arranged below the rolls, saidflexible suspension members extending through the table having theirupper ends secured to said support above the table and their lower endseifectively connected to said Weighted member located behind said drive.

References Cited by the Examiner UNITED STATES PATENTS 829,580 8/1906Folsom 273-55 2,258,802 10/1941 Pearlman 73-12 X 2,803,463 8/1957Congelli 198-29 X 3,085,659 4/1963 Ashmead 10425O X FOREIGN PATENTS32,217 2/ 1934 Germany.

EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner. A. L. LEVINE, E. A. SROKA, AssirtrmtExaminers.

1. A BUMPER COMPRISING A SUPPORT, A PLURALITY OF FLEXIBLE SUSPENSIONMEMBERS, AN IMPACT RECEIVING PLATE SECURED TO SAID FLEXIBLE SUSPENSIONMEMBERS INTERMEDIATE THEIR ENDS, THE UPPER ENDS OF SAID FLEXIBLESUSPENSION MEMBERS BEING SECURED TO SAID SUPPORT, A MASS, CONNECTINGMEANS FOR CONNECTING THE MASS TO THE LOWER ENDS OF SAID FLEXIBLESUSPENSION MEMBERS SUCH THAT MOVEMENT OF THE IMPACT RECIEVING PLATE FROMA REST POSITION MOVES THE MASS UPWARD.